Ice-making machine



Dec. 28, 1954 ER 2,697,919

Dec. 28, 1954 F. M. RAvER ICE-MAKING MACHINE 2 Sheets-Sheet 2 Filed Dec. ll, 1950 ,ff Al' f ATTOR 4,514

and the oil. The end of pipe 39 extends above the bottom wall of the surge tank so that only liquid refrigerant flows into it and the oil is collected in a tank 43 and is returned to the eompressor.

Referring now to Figure 2 wherein the details of construction of the ice-making unit 2 are shown, drum 24 has a rigid cylindrical wall 45 the outer surface of which forms the freezing surface and the ends of which are Closed by end bells 46 and 48. Each of the end bells is dished inwardly and has an extended cylindrical peripheral fiange which is welded to the adjacent edge of the wall 45. This construction prevents formation of ice on the extreme edges of the drum shell and is advantageous m that it provides a lighter, more compact and rugged structure than either a straight or outwardly dished end bell without undesirable reduction in ice making capacity. End bell 46 has welded to its center a supporting stud shaft 50 which projects through a mounting bearing assembly 52 and has keyed to its left-hand end a driving sprocliet Wheel 54. Sprocket wheel 54 is connected through a sprocket chain 56 to a driving sprocket 58 which is rotated by a motor 60 through a gear reduction mechanism 61.

The, right-hand end bell 48 has a central opening witliin which is welded a cylinder 62 together with a reenforcing ring 64, and the right-hand end of this cylinder 62 is welded to a rim or ring 66. Ring 66 in turn has clampcd to it a shaft-mounting plate 68 which has a central opening in which is welded a hollowed shaft 70. Shaft 70 extends to the right through a supporting bearing assembly 72 and provides support for the right-hand end of the cylindrical evaporator.

Projecting through shaft 70 is a stationary refrigerant outlet pipe 74 which terminates at the right in a stationary connecting bracket 76 and carries at the left a header 78 in which is mounted a refrigerant pipe 80. Pipe 80 projects downwardly to adjacent the bottom of the evaporator chamber and has its opening lower end so positioned that liquid in the bottom of the evaporator chamber is entrained in the refrigerant gas passing upwardly through pipe 80. Thus, the liquid refrigerant which collects in the bottom of the evaporator Chamber and the oil are withdrawn from the evaporator chamber by the outgoing refrigerant gas.

The stationary connecting bracket 76 is provided with an axial refrigerant inlet opening 82 to which the refrigerant supply pipe 40 is connected; and, projecting to the left from this bracket 76 is a refrigerant supply pipe 84. Pipe 84 extends through an opening in header 78, which assists in supporting the pipe. Pipe 84 extends to the left with its left-hand end closed and terminating adjacent the inner surface of bell 46. The joint between pipe 84 and header 78 is substantially gas tight which would not be possible with the Conventional spray nozzles. Pipe 84 is provided with a large number of pairs of perforations 86 which project the refrigerant in transverse spray patterns outwardly against the inner surface of the cylindrical evaporator wall 95. These refrigerant outlet openings 86 are of such size, number and relative positions that the individual sprays of each pair impinge on each other to give an atomizing effect such that the entire inner surface of shell 45 is constantly covered by a fine spray of refrigerant. Thus, flash evaporation occurs and the entire drum is cooled at an even rate.

During the ice-making operation the freezing surface is refrigerated and supplied with water to be frozen in the manner outlined above. The ice is then removed from the freezing surface in accordance with the principles of operation of the machines of the character referred to above which embody the invention covered in the aboveidentified patent to Raver. Refering to Figure 3, after the ice is severed from the freezing surface, it is carried away to the right by a doctor blade 88. Doctor blade 88 is mounted on brackets 90 and has a right-hand portion 92 down which the ice slides after moving to the right across the top of the doctor blade proper. The bracket 90 extends the full length of the machine and with the pivot point 96 and adjusting screws 98 allows multiple, independent, and localized adjustment of the doctor blade so proper clearance may be maintained the full length of the drum. The doctor blade is provided with relatively low temperature resistance heaters 94 which maintain the doctor blade at an elevated temperature. This temperature is such that the ice does not freze to the doctor blade and yet there is no objectionable heating of the ice.

As many possible embodiments may be made of the above invention and as many changes might be made in the embodiment above set forth, it is to be understood that all matter hereinbefore set forth, or shown in the accompanying drawing, is to be interpreted as illustrative and not in a liniiting sense.

I claim:

l. In ice-making apparatus of the character described, the combination of, a rotatable evaporator having an exterior cylindrical freezing surface upon which ice is formed, water sprayer means to supply water to said freezing surface, means to recirculate water which falls over the freezing surface and remains unfrozen, an iceremoving unit comprising a freely rotatable member having rigid wedging blades which are adapted to move into close proximity to said freezing surface and to wedge ice free therefrom, means pivotally mounting said scraper blade and a plurality of adjusting screws providing multiple and indeperident clearance adjustment, a scraper blade assembly positioiied adjacent said freezing surface and adapted to divert ice from said surface after it is freed by said ice-removing unit, said scraper blade assembly ineluding a blade portion and heater means to elevate the temperature of said blade portion, and refrigerant distributor means to refrigerate said freezing surface including a centrally positioned sprayer adapted to spray refrigerant against the inside surface of said evaporator throughout the zone of said freezing surface and means to withdraw and recirculate the unevaporated refrigerant.

2. In ice-making apparatus of the character described, the combination of, a cylindrical evaporator having an internal evaporator surface and an external ice freezing surface, means for mounting said evaporator, means to circulate refrigerant through said cylindrical evaporator at a rate in excess of the rate of evaporation of the refrigerant, refrigerant distributor means to refrigerate said surface including sprayer means adapted to spray refrigerant against the inside surface of said evaporator throughout the zone of said freezing surface, refrigerant discharge means to withdraw refrigerant from adjacent the lowest point of said internal evaporator surface to continuously withdraw the unevaporated refrigerant and oil together with the evaporated refrigerant, whereby said internal evaporator is maintained substantially liquid free.

3. Ice-making apparatus as described in claim 2 which includes, water sprayer means to supply water to said freezing surface, and means to recirculate water which falls over the freezing surface and remains unfrozen.

4. Apparatus as described in claim 3 which includes, a scraper blade assembly positioned adjacent said freezing surface and adapted to divert ice from said surface after it is freed by said ice-removing unit, said scraper blade assembly including a blade portion and heater means to elevate the temperature of said blade portion.

5. Apparatus as described in claim 2 which includes. a refrigerant discharge assembly within said cylindrical evaporator and including a fixed header and a pipe extending from said fixed header to closely adjacent the bottom of said evaporator.

6. In ice-making apparatus of the character described, the combination of, a rotatable evaporator having an exterior cylindrical freezing surface upon which ice is formed, an ice-removing unit comprising a freely rotatable member having rigid wedging blades which are adapted to move during rotation to and from close proximity to said freezing surface and to wedge ice free therefrom, refrigerant distributer means to refrigerate said freezing surface including centrally positioned sprayer means adapted to spray refrigerant against the inside surface of said evaporator throughout the zone of said freezing surface, bearing means mounting said rotatable evaporator witli its rotary axis so that oil and excess liquid refrigerant may be removed from a liquid zone at one end thereof, and a discharge pipe having an open end in said liquid zone, positionedto continuously withdraw the collected oil and excess liquid refrigerant.

7. An ice-making apparatus as described in claim 6 wherein said sprayer includes, a pipe extending along the axis of said cylindrical freezing surface and having a plurality of pairs of holes each oriented to project the refrigerant against the inner surface of said evaporator.

8. An ice-making apparatus as described in claim 7 wherein said pairs of holes are disposed to impinge the individual spray streams of each pair against each other to produce an atomizing effect whereby the interior surface of said evaporator is covered with a very fine spray1 and flash evaporation occurs.

9. In the art of makingice or the like, the steps of, spraying liquid refrigerant at a rate substantially in excess of the rate of evaporation into an evaporating cham- 5 ber and against the internal surface of a cylindrical evaporating zone thereby to refrigerate said zone and also to wash oil from said zone, withdrawing and recirculating the unevaporated refrgerant, continuously withdrawing from said evaporator the oil washed from said refrigerating zone, said withdrawal of said unevaporated refrigerant and said oil being substantially simultaneous and at a zone closely adjacent the bottom of said evaporating chamber to maintan said evaporating chamber substantially liquid free, and spraying water at a rate substantially in excess of the rate of freezing over the exterior of said evaporatng zone.

References Cited in the file of this patent Number UNITED STATES PATENTS Name Date Potter July 5, 1927 Gay June 19, 1934 Field Feb. 11, 1936 Taylor Dec. 8, 1936 Taylor Dec. 8, 1936 Buehler Dec. 13, 1938 1944 1945 Williams Mar. 12, 1946 

